Pateigk w



(No Model.)

P. W. LAMB.

GRATE BAR FOR FURNACES.

8 w M z 2 f n 0M [WW W a P wg mmmmmmmz E2225? Simi W m. D m E52; :25 555555 UNITED STATES PATENT OFFIC PATRICK W. LAMB, OF ALBANY, NE\V YORK.

GRATE-BAR FOR FURNACES.

SPECIFICATION forming part of Letters Patent No. 274,949, dated April 3, 1883.

Application filed February 6, 1883. (No model.)

T 0 all whom it may concern Be it known that I, PATRICK W. LAMB, a citizen of the United States, and a resident of Albany, in the county of Albany and State of New York, have invented certain new and useful Improvements in Grate-Bars for Furnaces, of which the following is a specification.

My invention relates to improvements in grate-bars for furnaces in which the grate'bar is composed of a series of short bars and slots arranged alternately and transversely to and between two parallel main side bars which have truss-bar portions made in solid connection with them, with their sides inclining downwardly and inwardly toward each other, the object being to stiffen the two main side bars of the grate and prevent the excessive warping ot'the same, and also to effect the heating ofthe upwardly-moving volume of currents of air before their passage into and through the slots between the short transverse bars ofthe grate-bar;

second, to provide with each grate-barat the border edges of each main side bar of the gratebar a series of semicircular notches or horizontall y-formed recesses, which, when two or more said grate-bars are nested together within the furnace, (toform thegratedtire-bed ofthesame,) will form a series of vertical ports or openings between two adjoining grate bars, through which openings or ports air will have free passage,at'ter being heated by the downwardlyprojecting sides of the truss-bars, upward between the neighboring grate bars, the object being to eflect the cooling or the reduction of the temperature of the outer edges of the main bars of the neighboring gratebars by means of a free supply of air passing through the said openings, which air will in its passage absorb a portion of the heat of said bars and be introduced to within the body ofthe incandescent coal in a highly heated condition. I attain these objects by means of the construction and arrangement of the several portions of the grate-bar, as illustrated in the accompanying drawings, in which- Figure l is a plan view of two neighboring grate-bars having my improvements and arranged as intended to beused within a furnace. Fig. 2 is a longitudinal sectional view taken at line No. 1 in Fig. l; and Fig. 3 'is a crosssectional view taken at line No. 2 in Fig. 1.

Similar letters refer to similar parts through; out the several views.

In the drawings, A A represent two of my improved gratebars arranged neighboring each other, as intended to be used in afurnace. Each said grate-bar is made in its several portions the same as the other, in which the two parallel side portions or bars, a a, comprise the two main side bars of a single grate-bir. These main side bars are connected together at their ends by bars a a, and have arranged between them, at short intervals apart, to form slots 8 s, the short transverse bars b b, which are made with a depth of vertical-extension about equal to the vertical extension of the main side-bar portions a a, as illustrated and indicated by full and dotted lilies in Figs. 2 and 3.

Cast in solid connection with the main sidebar portionsa a, and extended downward from the lower side of the same, are truss-bar portions 0 c of my improved grate-bar A. These trussbar portions are cast in solid connection with the main side-bar portions in such a manner that they will incline slightly inward toward each other, as shown in Fig. 3, so that the-opening between the truss-bar portions of each grate-bar A will be greater at the line of the'lower plane of slots as and transverse bars I) 11 than at the plane of the loweredges of said trnss'bar portions 0 c, as shown.

'By this manner of construction and arrangement of the above-described portions; of the grate-bar A there is produced a wide and deep opening, 0, between the inclined trussbar portions 0 c, in which the lower portion of said opening will be more contracted than the upper portion thereof, and will in a measure restrict or limit the volume of air passing into opening 0 and allow it to expand within the upper and wider portion of the same, while at the same time the inclining of said truss-bar portions of the grate will cause the downwardly-flashing ot' the heat of the fire above to strike strongly on the inner side surfaces of the said bars, and thereby raise the temperature of the portions of the same to near that of the main sidebars, a a, with which they are connected, so that the heat will cause about an equal expansion of both the main side-bar portions a and the truss-bar portions 0, that both will be preserved from warping or twistin g, as heretofore in this class of grate-bars.

Made with the outer side edges ofeach main side-bar portion is flange-rim d. In the outer edges of these flange-rims are made a series of semicircular horizontal notches or recesses, e e. When these notched flange-rims of two neighboring grate-bars are placed contiguous with each other, as shown in Figs. 1 and 3, there will be produced a series of vertical ports or openings, 6 e, which will operate as passageways through which a liberal supply of air will have passage from below to the body of the incandescent coal on the grate-bed. When two grate-bars are placed neighboring to each other, as shown, there will be produced between the trussbar portions 0 c of the two neighboring grate-bars the opening 0, the walls of which will incline downwardlv and outwardly from each other, as shown in Fig. 3. The form of sides 0t said opening 0 is shown to be the reverse to that of the sides of openings O, and this reversed form of side walls of opening effects in one respect a reversed operation from thathad by the contracted form of side walls of opening 0, for, when the forceblast of air is admitted into the ash-pit of the furnace and below the grate-bars, the pressure of the air upward through opening 0 will force a greater volume of air proportionately through the same, and between its upwardly and inwardly inclined walls than would he were the walls vertical or contracted, and the currents of airwill pass in larger volume and with greater rapidity through the series of ports or openings 6 0 than it will through those openings made with vertical side walls formed by truss-bar portions of grates, as heretofore made and arranged. This greater volume of air and more rapid passage of the same (under pressure of the force-blast) will effect a lowering of the temperature of the side main bars, a a, of the grate-bars by absorbing heat from the same, while the air itself will become more highly heated before its full discharge into the body of the fuel on the grate, while the reduction of the temperature of the metal of the main side bars of the grate-bar will cause the said side bars and the truss-bar portions made solid with it to be of nearly the same temperature from top to bottom edges of the same, and thereby contribute to prevent the warpage and twisting of the same, which is very desirable.

and inwardly contracting or inclining sidesof the truss-bar portions ot'each grate-bar, whereby the sides of the same will become more highly heated by the downward flash of the heat through slots 8 8 than they are heated when said sides are vertical; and when several of the said grate-bars are arranged side 7 Havingdescribed myinventioinwh at I claim,

and desire to secure by Letters Patent, is

1. A grate-bar for furnaces, having a series of alternate short bars, I), and slots 8 arranged transversely between twoparallel main side-bar portions, a Ct, which are stiffened by truss-bar portions 0 0, made in solid connection with said main side-bar portions, the said truss-bar portions being made to incline at their lower portions inwardly, so as to form a gradually upwardly expanded chain beror opening, 0, in which its sides will receive the downwardlyreflected heat of the fire above, substantially as and for the purpose set forth.

2. The combination and arrangement of two or more grate-bars, A A, which are perforated or slotted, and have their main bars or side portions, to a, stifi'ened by truss-bar portions 0 0, made in solid connection with said side portions, and set relatively inclined inwardly, so as to be heated by the reflected heat from the tire above and produce a chamber or opening, 0, which will be expanded gradually upwardly, and also have a series of horizontal recesses or notches, e 6, made in the flanged rims d d of each said grate-bar, whereby when said grate-bars A A are placed together neighborly a gradually upwardly contracting opening or chamber, 0, will be produced, which will have communication with the fire above through notches e c, all for operations set forth, substantially as described.

PATRICK \V. LAMB.

Witnesses:

JAMES M. SHATTUCK, ALEX. SELKIRK. 

